Cartwright and Munro argued that extrapolation of findings from randomized controlled trials to other settings can be difficult because information about the underlying causal structure and subgroups is often not available. They advocated the use of ‘capacities’ – that is fixed causal contributions – in predicting effects of interventions. In psychiatry, it is often not possible to determine what the fixed causal contributions are and one can only establish ‘approximate capacities’. However, using ‘approximate capacities’ does imply a different way of (...) evaluating health services, especially combined interventions. In health service research, if different studies, randomized controlled trials or other designs, have given different outcomes, the best way to investigate the effectiveness of a particular way of service organization is not to conduct more randomized controlled trials. It is preferable to study the effects of certain elements of the complex intervention, which have been tested before in other settings, that is investigating ‘approximate capacities’. One should check whether the separate elements do form a part of the complex intervention in practice and whether they have the same effect as in other studies and if not, why not. This enhances knowledge about the underlying causal structure and increases the possibility of extrapolation of the findings. (shrink)

Evidence-based psychiatry (EBP) has arisen through the application of evidence-based medicine (EBM) to psychiatry. However, there may be aspects of psychiatric disorders and treatments that do not conform well to the assumptions of EBM. This paper reviews the ongoing debate about evidence-based psychiatry and investigates the applicability, to psychiatry, of two basic methodological features of EBM: prognostic homogeneity of clinical trial groups and quantification of trial outcomes. This paper argues that EBM may not be the best way to pursue psychiatric (...) knowledge given the particular features of psychiatric disorders and their treatments. As a result, psychiatry may have to develop its own standards for rigour and validity. This paper concludes that EBM has had a powerful influence on how psychiatry investigates and understands mental disorders. Psychiatry could influence EBM in return, reshaping it in ways that are more clinically useful and congruent with patients’ needs. (shrink)

The question what scientific progress means for a particular domain such as medicine seems importantly different from the question what scientific progress is in general. While the latter question received ample treatment in the philosophical literature, the former question is hardly discussed. I argue that it is nonetheless important to think about this question in view of the methodological choices we make. I raise specific questions that should be tackled regarding scientific progress in the medical sciences and demonstrate their importance (...) by means of an analysis of what evidence-based medicine (EBM) has, and has not, to offer in terms of progress. I show how critically thinking about EBM from the point of view of progress can help us in putting EBM and its favoured methodologies in the right perspective. My conclusion will be that blindly favouring certain methods because of their immediately tangible short-term benefits implies that we parry the important question of how best to advance progress in the long run. This leads us to losing sight of our general goals in doing research in the medical sciences. (shrink)